Disclosed herein are silicon-containing or silicon-based dielectric films or materials, and methods and compositions of forming the same.
The silicon-based dielectric films described herein include, but not limited to, non-stoichiometric silicon carbide, amorphous silicon, silicon carbonitride, or silicon nitride for use in various electronic applications. In certain embodiments, the dielectric films include other elements besides silicon and carbon. These other elements may sometimes be intentionally added into the compositional mixture via the deposition process depending upon the resultant application of the film or desired end-properties. For example, the element nitrogen (N) may be added to the silicon-based films to form a carbonitride or silicon nitride film to provide a certain dielectric performance such as, without limitation, a lower leakage current. Depending upon the application, however, certain elements in the film may be undesirable even at lower concentration levels.
Silicon carbide films are typically deposited using the precursor 1,4-disilabutane (1,4-DSB). US Publ. No. 2010/233886 described methods of forming silicon-based films comprising Si, such as, but not limited to, Si oxide, Si oxycarbide, Si carbide, and combinations thereof, that exhibit at least one of the following characteristics: low wet etch resistance, a dielectric constant of 6.0 or below, and/or can withstand a high temperature, rapid thermal anneal process.
While the prior art has disclosed the use of 1,4-disilabutane as precursor for chemical vapor deposition (CVD) of silicon-containing films such as, silicon carbide films with silicon content higher than about 55% according to X-ray photoelectron spectroscopy (XPS), there is a need to deposit silicon carbide films or materials having a silicon content less than about 55%. It is believed that the reason that the SiC films deposited from 1,4-disilabutane had a silicon content greater than >55% Si was because the Si was bound to itself forming Si—Si bonds. These Si—Si bonds make the film susceptible to damage during subsequent process integration steps such as, for example, exposure to O2 plasma treatment or ashing. Hence, there is a need in the art to provide develop alternative precursors and methods using same to provide silicon containing films where the silicon content of the film is less than about 55% as measured by XPS. It is also desirable to have robust films of high density (a density of 2 grams/cubic centimeter (g/cc) or greater) to withstand further processing steps during integration.